Check the size printed on your current sidewall, then confirm it against the driver door sticker or the vehicle handbook. Many vehicles that use 275/40 R21 run it on the front axle with a wider rear size, so match what is specified for your wheel position. If your car lists more than one approved size, stick to the one that matches your wheel diameter and axle. If you are unsure, use the vehicle lookup or contact support before ordering.
Use the load index and speed rating recommended by the vehicle manufacturer, as this size is often fitted to heavier, high-powered SUVs. You will commonly see higher load ratings and XL (Extra Load) options available, which are designed to carry more weight at the correct pressure. You can choose a higher load index than specified, but never lower. Select the correct rating in the filters before adding tyres to your basket.
Yes, provided the front and rear sizes match the manufacturer-approved staggered combination for your exact model and wheel package. Replace tyres in pairs on the same axle, and keep the same brand and tread pattern across that axle for balanced grip and braking. On xDrive, quattro and other AWD systems, mismatched rolling circumference can cause drivetrain issues, so check tolerances carefully. If you are changing sizes, confirm approval first rather than guessing.
Summer tyres suit warm-weather performance and are a popular choice for 21-inch SUV fitments focused on handling. Winter tyres are best when temperatures regularly drop below 7C or you expect snow and ice, and you should look for the 3PMSF marking. All-season tyres provide a year-round compromise for mixed UK conditions, especially if you want one set. Choose the type that matches your local climate and driving style, then compare models within that category.
Run-flat versions are available from several premium manufacturers in 275/40 R21, and they are often fitted as original equipment on certain SUVs. If your vehicle was supplied with run-flats and has no spare wheel, staying with the same type keeps the intended mobility plan after a puncture. Switching to standard tyres can improve ride comfort, but you should ensure you have a puncture repair kit and that your car is compatible. Check your current tyre sidewall for run-flat markings before you buy.
